CO2 conversion to formic acid in a single-step reaction was investigated by incorporating MoSe2 nanoparticles into a cryogel-based reactor system, resulting in a formate dehydrogenase (FDH) enzyme-mimicking system. MoSe2 nanoparticles were synthesized via the microwave synthesis method, and they took part as the cofactor of the enzymatic system. Following, in combination with MACys-Ru(bipyr)2-MACys, MoSe2 nanoparticles were used as the cofactor of the conversion reaction in the MACys-Ru(bipyr)(2)-MACys-co-p(HEMA) cryogel column-based reactor system. Synthesized nanoparticles were characterized by Fourier transformed infrared spectroscopy, field emission-scanning electron microscopy, transmission electron microscopy, and energy dispersive x-ray spectroscopy. The conversion reaction was monitored using high-pressure liquid chromatography, and the parameters affecting the conversion yield (e.g., pH change and reusability of the reactor) were investigated. The results showed that the obtained mimic FDH-based CO2 conversion column system worked like a reactor in the conversion of CO2 into formic acid. Besides, the developed cryogenic reactor provided a reusable single-step conversion reaction with a high yield at room temperature in mild conditions.